示例#1
0
/* Emit x86/x64 text relocations. */
static void emit_asm_reloc_text(BuildCtx *ctx, uint8_t *cp, int n,
				const char *sym)
{
  const char *opname = NULL;
  if (--n < 0) goto err;
  if (cp[n] == 0xe8) {
    opname = "call";
  } else if (cp[n] == 0xe9) {
    opname = "jmp";
  } else if (cp[n] >= 0x80 && cp[n] <= 0x8f && n > 0 && cp[n-1] == 0x0f) {
    opname = jccnames[cp[n]-0x80];
    n--;
  } else {
err:
    fprintf(stderr, "Error: unsupported opcode for %s symbol relocation.\n",
	    sym);
    exit(1);
  }
  emit_asm_bytes(ctx, cp, n);
  if (strncmp(sym+(*sym == '_'), LABEL_PREFIX, sizeof(LABEL_PREFIX)-1)) {
    /* Various fixups for external symbols outside of our binary. */
    if (ctx->mode == BUILD_elfasm) {
      if (LJ_32)
	fprintf(ctx->fp, "#if __PIC__\n\t%s lj_wrap_%s\n#else\n", opname, sym);
      fprintf(ctx->fp, "\t%s %s@PLT\n", opname, sym);
      if (LJ_32)
	fprintf(ctx->fp, "#endif\n");
      return;
    } else if (LJ_32 && ctx->mode == BUILD_machasm) {
      fprintf(ctx->fp, "\t%s L%s$stub\n", opname, sym);
      return;
    }
  }
  fprintf(ctx->fp, "\t%s %s\n", opname, sym);
}
/* Emit relocation for the incredibly stupid OSX assembler. */
static void emit_asm_reloc_mach(BuildCtx *ctx, uint8_t *cp, int n,
				const char *sym)
{
  const char *opname = NULL;
  if (--n < 0) goto err;
  if (cp[n] == 0xe8) {
    opname = "call";
  } else if (cp[n] == 0xe9) {
    opname = "jmp";
  } else if (cp[n] >= 0x80 && cp[n] <= 0x8f && n > 0 && cp[n-1] == 0x0f) {
    opname = jccnames[cp[n]-0x80];
    n--;
  } else {
err:
    fprintf(stderr, "Error: unsupported opcode for %s symbol relocation.\n",
	    sym);
    exit(1);
  }
  emit_asm_bytes(ctx, cp, n);
  fprintf(ctx->fp, "\t%s %s\n", opname, sym);
}